WO2021187258A1

WO2021187258A1 - Material for acoustic matching layer, acoustic matching sheet, acoustic wave probe, ultrasonic probe, acoustic wave measuring device, ultrasonic diagnostic device, and method for producing acoustic wave probe

Info

Publication number: WO2021187258A1
Application number: PCT/JP2021/009413
Authority: WO
Inventors: 和博 ▲濱▼田; 中井　義博; 林　大介
Original assignee: 富士フイルム株式会社
Priority date: 2020-03-18
Filing date: 2021-03-10
Publication date: 2021-09-23
Also published as: JPWO2021187258A1; EP4122399A4; CN115209811A; JP7242961B2; US20230037985A1; EP4122399A1

Abstract

Provided are: a material for an acoustic matching layer; an acoustic matching sheet; an acoustic wave probe; an ultrasonic probe; an acoustic wave measuring device; an ultrasonic diagnostic device; and a method for producing an acoustic wave probe, by which the acoustic impedance of an acoustic matching sheet obtained by suppressing the decrease in sound velocity due to the addition of tungsten carbide particles can be effectively increased while using, as a metal filler, the tungsten carbide particles having a high specific gravity, and variations in the acoustic characteristics within the acoustic matching sheet can also be suppressed. The material for an acoustic matching layer contains the following components (A), (B), and (C).　(A) Epoxy resin (B) Curing agent (C) Surface-treated tungsten carbide particles which are surface-treated with a surface treating agent containing at least one among an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound

Description

Material for acoustic matching layer, acoustic matching sheet, acoustic wave probe, ultrasonic probe, acoustic wave measuring device, ultrasonic diagnostic device, and manufacturing method of acoustic wave probe.

The present invention relates to a material for an acoustic matching layer, an acoustic matching sheet, an acoustic wave probe, an ultrasonic probe, an acoustic wave measuring device, an ultrasonic diagnostic device, and a method for manufacturing an acoustic wave probe.

The acoustic wave measuring device uses an acoustic wave probe that irradiates an object to be inspected such as a living body with an acoustic wave, receives the reflected wave (echo), and outputs a signal. The reflected wave received by this acoustic wave probe is converted into an electric signal and displayed as an image. Therefore, by using the acoustic wave probe, the inside of the test object can be visualized and observed.

As the acoustic wave, ultrasonic waves, photoacoustic waves, and the like are appropriately selected according to the test object and the measurement conditions.
For example, an ultrasonic diagnostic device, which is a kind of acoustic wave measuring device, transmits ultrasonic waves toward the inside of the test object, receives the ultrasonic waves reflected by the tissue inside the test target, and displays them as an image. ..
Further, the photoacoustic wave measuring device, which is a kind of acoustic wave measuring device, receives the acoustic wave radiated from the inside of the test object by the photoacoustic effect and displays it as an image. The photoacoustic effect is an acoustic wave (acoustic wave) when an electromagnetic wave pulse such as visible light, near-infrared light, or microwave is applied to an object to be examined, and the object to be examined absorbs the electromagnetic wave to generate heat and thermally expand. This is a phenomenon in which electromagnetic waves are typically generated.

Since the acoustic wave measuring device transmits and receives acoustic waves to and from the test object, the acoustic wave probe is required to match the acoustic impedance with the test target (typically the human body). To meet this requirement, the acoustic wave probe is provided with an acoustic matching layer. This will be described by taking as an example a probe for an ultrasonic diagnostic apparatus (also referred to as an ultrasonic probe), which is a kind of acoustic wave probe.
The ultrasonic probe includes a piezoelectric element that transmits and receives ultrasonic waves and an acoustic lens that comes into contact with a living body, and an acoustic matching layer is arranged between the piezoelectric element and the acoustic lens. The ultrasonic waves oscillated from the piezoelectric element pass through the acoustic matching layer, further pass through the acoustic lens, and are incident on the living body. There is usually a difference in the acoustic impedance (density x speed of sound) between the acoustic lens and the living body. If this difference is large, the ultrasonic waves are easily reflected on the surface of the living body, and the incident efficiency of the ultrasonic waves into the living body is lowered. Therefore, the acoustic lens is required to have an acoustic impedance characteristic close to that of a living body.
On the other hand, the difference in acoustic impedance between the piezoelectric element and the living body is generally large. Therefore, the difference in acoustic impedance between the piezoelectric element and the acoustic lens is usually large. Therefore, in the case of a laminated structure of the piezoelectric element and the acoustic lens, the ultrasonic waves emitted from the piezoelectric element are reflected on the surface of the acoustic lens, and the incident efficiency of the ultrasonic waves on the living body is lowered. In order to suppress the reflection of this ultrasonic wave, the above-mentioned acoustic matching layer is provided between the piezoelectric element and the acoustic lens. The acoustic impedance of the acoustic matching layer takes a value between the acoustic impedance of the living body or the acoustic lens and the acoustic impedance of the piezoelectric element, thereby improving the efficiency of propagation of ultrasonic waves from the piezoelectric element to the living body. Further, in recent years, the acoustic matching layer has a multi-layer structure in which a plurality of acoustic matching sheets (sheet-shaped acoustic matching layer materials) are laminated, and the acoustic impedance is inclined from the piezoelectric element side to the acoustic lens side. , The development of an acoustic matching layer with more efficient propagation of ultrasonic waves is underway.

The acoustic impedance of the acoustic matching layer can be adjusted by blending a filler such as metal particles with the material for forming the acoustic matching layer. For example, Patent Document 1 describes a resin composition for an acoustic matching layer containing a binder containing a resin such as an epoxy resin and surface-treated metal particles.

International Publication No. 2019/088148

In the multi-layered acoustic matching layer, the above-mentioned gradient of the acoustic impedance is designed so that the closer to the piezoelectric element, the larger the acoustic impedance of the acoustic matching sheet, and the closer to the acoustic lens, the smaller the acoustic impedance of the acoustic matching sheet. .. That is, an acoustic matching sheet close to the acoustic impedance of the piezoelectric element (usually about 25 mile) on the piezoelectric element side and close to the acoustic impedance of the living body (1.4 to 1.7 mile in the human body) on the acoustic lens side is obtained. Be done.
The acoustic impedance of an acoustic matching sheet is determined by multiplying the density of the sheet constituent materials and the speed of sound. Therefore, when trying to increase the acoustic impedance of the acoustic matching sheet used on the piezoelectric element side, it is conceivable to use a material having a high density and a high sound velocity. However, it has been found that when a filler such as a metal having a large specific gravity is contained in the acoustic matching sheet in order to increase the acoustic impedance, the density of the sheet can be improved, but the sound velocity of the sheet is lowered. Therefore, when a filler such as a metal having a large specific gravity is used for the acoustic matching sheet, it is necessary to suppress the above-mentioned decrease in sound velocity in order to use this sheet on the piezoelectric element side. However, Patent Document 1 does not describe this point.

INDUSTRIAL APPLICABILITY The present invention can effectively increase the acoustic impedance of an acoustic matching sheet obtained by suppressing a decrease in sound velocity due to the blending of tungsten carbide particles while using tungsten carbide particles having a large specific gravity as a metal filler. An object of the present invention is to provide a material for an acoustic matching layer that can suppress variations in acoustic characteristics in an acoustic matching sheet.
Further, in the present invention, while using tungsten carbide particles as the metal filler, the decrease in sound velocity due to the compounding of the tungsten carbide particles is suppressed, the acoustic impedance is effectively enhanced, and the acoustic matching with little variation in the acoustic characteristics in the sheet is performed. The task is to provide a sheet.
Another object of the present invention is to provide an acoustic wave probe and an ultrasonic probe using the acoustic matching sheet, and an acoustic wave measuring device and an ultrasonic diagnostic device using these.
Another object of the present invention is to provide a method for manufacturing an acoustic wave probe using the above-mentioned material for an acoustic matching layer.

As a result of diligent studies in view of the above problems, the present inventors have prepared an acoustic matching sheet by subjecting an epoxy resin and a curing agent to a curing reaction in the presence of tungsten carbide particles treated with a specific surface treatment agent. It has been found that the decrease in sound velocity that normally occurs due to the inclusion of particles can be suppressed, and that this acoustic matching sheet has little variation in acoustic characteristics. The present invention has been completed based on these findings.

The above-mentioned problems of the present invention have been solved by the following means.
<1>
A material for an acoustic matching layer containing the following components (A), (B) and (C).
(A) Epoxy resin (B) Hardener (C) A surface containing at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound and a titanium alkoxide compound. Surface-treated tungsten carbide particles surface-treated with a treatment agent <2>
The material for an acoustic matching layer according to <1>, wherein the component (B) contains at least one of a primary amine and a secondary amine.
<3>
The material for an acoustic matching layer according to <1> or <2>, wherein the surface treatment agent contains at least one of an aminosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.
<4>
The material for an acoustic matching layer according to any one of <1> to <3>, wherein the surface treatment agent contains at least one of an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.
<5>
The material for an acoustic matching layer according to any one of <1> to <4>, wherein the surface treatment agent contains at least one of a zirconium alkoxide compound and a titanium alkoxide compound.
<6>
The material for an acoustic matching layer according to any one of <1> to <5>, wherein the aluminum alkoxide compound contains at least one of an acetonate structure and an acetylate structure.
<7>
The material for an acoustic matching layer according to any one of <1> to <6>, wherein the aluminum alkoxide compound contains at least one compound represented by the following general formula (1).
General formula (1): R ^1a _m1- Al- (OR ^2a ) _3-m1
R ^1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R ^2a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or _-SO 2 ^{R S1.} ^RS1 represents a substituent.
m1 is an integer of 0 to 2.
<8>
The material for an acoustic matching layer according to any one of <1> to <7>, wherein the zirconium alkoxide compound contains at least one of an acetonate structure and an acetylate structure.
<9>
The material for an acoustic matching layer according to any one of <1> to <8>, wherein the zirconium alkoxide compound contains at least one compound represented by the following general formula (2).
General formula (2): R ^1b _m2- Zr- (OR ^2b ) _4-m2
R ^1b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R ^2b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or _-SO 2 ^{R S2.} ^RS2 indicates a substituent.
m2 is an integer from 0 to 3.
<10>
The material for an acoustic matching layer according to any one of <1> to <9>, wherein the titanium alkoxide compound contains at least one atom of N, P and S.
<11>
The material for an acoustic matching layer according to any one of <1> to <10>, wherein the titanium alkoxide compound contains at least one compound represented by the following general formula (3).
General formula (3): R ^1c _m3- Ti- (OR ^2c ) _4-m3
R ^1c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R ^2c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or _-SO 2 ^{R S3.} ^RS3 indicates a substituent.
m3 is an integer from 0 to 3.
<12>
The acoustic matching according to any one of <1> to <11>, wherein the content of the surface treatment agent in the component (C) is 1 to 50 parts by mass with respect to 100 parts by mass of the tungsten carbide particles. Material for layers.
<13>
The material for an acoustic matching layer according to any one of <1> to <12>, wherein the tungsten carbide particles constituting the component (C) have an average primary particle size of 1 to 10 μm.
<14>
An acoustic matching sheet obtained by curing the material for an acoustic matching layer according to any one of <1> to <13>.
<15>
An acoustic wave probe having the acoustic matching sheet according to <14>.
<16>
An ultrasonic probe having the acoustic matching sheet according to <14>.
<17>
An acoustic wave measuring device including the acoustic wave probe according to <15>.
<18>
An ultrasonic diagnostic apparatus including the acoustic wave probe according to <15>.
<19>
A method for manufacturing an acoustic wave probe, which comprises forming an acoustic matching layer using the material for an acoustic matching layer according to any one of <1> to <13>.

In the description of the present specification, the "metal alkoxide compound (specifically, for example, a titanium alkoxide compound, an aluminum alkoxide compound, and a zirconium alkoxide compound described later)" has a structure in which at least one alkoxy group is bonded to a metal atom. Means a compound having. This alkoxy group may have a substituent. The substituent may be monovalent or divalent (eg, an alkylidene group). Further, two alkoxy groups bonded to one metal atom may be bonded to each other to form a ring.
In the description of the present specification, unless otherwise specified, when a plurality of groups having the same code are present in the general formula indicating a compound, they may be the same or different from each other. Further, the group indicated by each group (for example, an alkyl group) may further have a substituent.
Further, in the present specification, "-" is used in the meaning of including the numerical values described before and after it as the lower limit value and the upper limit value.

The material for the acoustic matching layer of the present invention uses tungsten carbide particles having a large specific gravity as the metal filler, and effectively suppresses the decrease in sound velocity due to the blending of the tungsten carbide particles to effectively obtain the acoustic impedance of the acoustic matching sheet. It can be enhanced, and variations in acoustic characteristics within this acoustic matching sheet can also be suppressed.
Further, in the acoustic matching sheet of the present invention, while using tungsten carbide particles as the metal filler, the decrease in sound velocity due to the blending of the tungsten carbide particles is suppressed, the acoustic impedance is effectively enhanced, and the acoustic characteristics in the sheet vary. There are few.
Further, the acoustic wave probe, the ultrasonic probe, the acoustic wave measuring device and the ultrasonic diagnostic device of the present invention have an acoustic matching sheet having the above-mentioned excellent characteristics.
Further, according to the method for manufacturing an acoustic wave probe of the present invention, an acoustic wave probe using the above-mentioned material for an acoustic matching layer can be obtained.

FIG. 1 is a perspective transmission view of an example of a convex type ultrasonic probe, which is an aspect of an acoustic wave probe.

<< Material for acoustic matching layer >>
The material for an acoustic matching layer of the present invention (hereinafter, also simply referred to as “material”) contains the following components (A), (B) and (C).
(A) Epoxy resin (B) Hardener (C) Surface treatment of at least one of aminosilane compound, mercaptosilane compound, isocyanatosilane compound, thiocyanatosilane compound, aluminum alkoxide compound, zirconium alkoxide compound and titanium alkoxide compound. Surface-treated tungsten carbide particles surface-treated with an agent

The material of the present invention includes a form of a composition obtained by mixing the above components (A) to (C). When the material of the present invention is in the form of a composition for an acoustic matching layer (hereinafter, also referred to as "composition" of the present invention), that is, it is contained in a container in a state where the above components (A) to (C) are mixed. If so, the composition should be stored at −10 ° C. or lower so that the components (A) to (C) do not react or are sufficiently suppressed to maintain a stable state of each component. Is preferable.

The material of the present invention includes a form of a set for an acoustic matching layer (hereinafter, also referred to as a "set" of the present invention) in which the above components (A) to (C) are contained in a container in a separated state. Examples of the form of this set include the following forms (i) to (iv).

(I) A form in which the above-mentioned components (A) and (B) and the above-mentioned component (C) are separately contained and mixed at the time of use.
(Ii) A form in which the above-mentioned components (A) and (C) and the above-mentioned component (B) are separately contained and mixed at the time of use.
(Iii) A form in which the above-mentioned component (A) and the above-mentioned components (B) and (C) are separately contained and mixed at the time of use, and
(Iv) A form in which the above components (A) to (C) are separately contained and mixed at the time of use.

In the above forms (i) to (iv), it is preferable to store the set of the present invention at −10 ° C. or lower in order to maintain a stable state in which each component is maintained.
The material of the present invention may be stored in a light-shielded manner, if necessary.

If the acoustic matching sheet contains a filler having a large specific gravity, the sound velocity of the sheet decreases. It is presumed that this is because the inertia when the acoustic wave (mainly the longitudinal wave) enters the acoustic matching sheet causes the phase to be delayed at the filler interface and the sound velocity to decrease. However, the acoustic matching sheet of the present invention obtained by curing the material of the present invention having the above structure suppresses a decrease in ^{sound velocity (sound velocity = (sheet elastic modulus / sheet density) 1/2) and acoustically.} There is little variation in characteristics. The reasons for these are not yet clear, but are presumed as follows. In the acoustic matching sheet of the present invention, the component (C) is surface-treated with a specific surface treatment agent, so that a structure contributing to the improvement of the elastic modulus of the sheet is formed at the interface between the component (C) and the matrix resin. It is considered that the elastic modulus is increased by a slight aggregation of a small amount of the component (C) while suppressing the aggregation of the component (C).

<(A) Epoxy resin>
As the epoxy resin used in the present invention, ordinary epoxy resins can be used, and for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin and phenol novolac type epoxy resin are preferable.

The bisphenol A type epoxy resin that can be used in the present invention is not particularly limited, and those generally used as the main agent of the epoxy adhesive can be widely used. Preferred specific examples include bisphenol A diglycidyl ether (jER825, jER828 and jER834 (all trade names), manufactured by Mitsubishi Chemical Corporation) and bisphenol A propoxylate diglycidyl ether (manufactured by Sigma-Aldrich).

The bisphenol F type epoxy resin that can be used in the present invention is not particularly limited, and those generally used as the main agent of the epoxy adhesive can be widely used. Preferred specific examples include bisphenol F diglycidyl ether (trade name: EPICLON830, manufactured by DIC Corporation) and 4,4'-methylenebis (N, N-diglycidyl aniline).

The phenol novolac type epoxy resin that can be used in the present invention is not particularly limited, and those generally used as the main agent of the epoxy adhesive can be widely used. Such a phenol novolac type epoxy resin is sold by, for example, Sigma-Aldrich as product number 406775.

<(B) Hardener>
As the curing agent, those known as curing agents for epoxy resins (preferably organic compounds) can be used without particular limitation. For example, aliphatic amines, aromatic amines, dicyandiamides, dihydrazide compounds, acid anhydrides, phenol compounds and the like can be mentioned.
At least one of a primary amine (a compound having an unsubstituted amino group) and a secondary amine (a compound having a monosubstituted amino group) from the viewpoint of increasing the crosslink density and reducing the variation in the acoustic properties of the obtained material. Is preferable, and primary amine is more preferable. Compounds having both an unsubstituted amino group and a monosubstituted amino group shall be classified as secondary amines. Specific examples of the compound having at least one of an unsubstituted amino group and a monosubstituted amino group include isophorone diamine, mensen diamine, m-phenylenediamine, polyether amine, polyamide amine, triethylenetetramine and piperidine. Can be mentioned.

<(C) Surface-treated tungsten carbide particles>
The component (C) is surface-treated with a surface treatment agent containing at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound and a titanium alkoxide compound. Also, surface-treated tungsten carbide particles. The component (C) is a component different from the component (B).

The average primary particle diameter of the tungsten carbide particles constituting the surface-treated tungsten carbide particles used in the present invention is not particularly limited, and the point of suppressing the decrease in sound velocity of the acoustic matching sheet and the point of reducing the variation in the acoustic characteristics of the acoustic matching sheet. Therefore, 1 to 30 μm is preferable, 1 to 20 μm is more preferable, and 1 to 10 μm is further preferable.
The average primary particle size of the component (C) is preferably 1 to 30 μm, more preferably 1 to 20 μm, and even more preferably 1 to 10 μm.

The average primary particle size can be obtained by averaging the particle size measured by a transmission electron microscope (TEM). That is, the shortest diameter and the longest diameter of one tungsten carbide particle in the electron micrograph taken by TEM are measured, and the arithmetic mean value is obtained as the particle diameter of one tungsten carbide particle. In the present invention, the particle sizes of 300 randomly selected tungsten carbide particles are averaged and determined as the average primary particle size.

Commercially available tungsten carbide particles can be used, and examples thereof include WC (trade name) manufactured by Allied Materials.

The surface treatment agent used in the present invention is an aminosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound from the viewpoint of suppressing the decrease in sound velocity of the acoustic matching sheet and reducing the variation in the acoustic characteristics of the acoustic matching sheet. It is preferable to contain at least one kind, more preferably at least one kind of aluminum alkoxide compound, zirconium alkoxide compound and titanium alkoxide compound, and further preferably containing at least one kind of zirconium alkoxide compound and titanium alkoxide compound.
Hereinafter, the surface treatment agent used in the present invention will be specifically described.

(Aminosilane compound)
The aminosilane compound (silane compound having an amino group) is preferably a silane coupling agent having an amino group. However, it is preferable that the aminosilane compound does not have a Si—N—Si structure. In the "Si—N—Si structure”, each silicon atom has three bonds and the nitrogen atom has one bond.

The aminosilane compound preferably contains at least one compound represented by the following general formula (A).

In the formula, R ¹ and R ² represent a hydrogen atom or a substituent. L ^1a is a single bond, an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -O-, -S-, -NR ^a- , an ester bond, a thioester bond, an amide bond, a thioamide bond or a sulfonyl group, or a group thereof. A divalent group consisting of a combination of two or more bonds is shown. ^Ra represents a hydrogen atom or a substituent. Y ^1a represents a hydroxy group or an alkoxy group. Y ^2a and Y ^3a represent a hydroxy group, an alkoxy group, an alkyl group or a ketooxime group.

The ^{substituents that can be taken as R 1} and R ² are, for example, an alkyl group (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms) and an alkenyl group (preferably 2 to 12 carbon atoms, more preferably carbon atoms). Numbers 2 to 8), alkynyl groups (preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms), aryl groups (preferably 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms). .. These substituents may further have a substituent, and examples of such a substituent include the above-mentioned substituents and amino groups mentioned as possible substituents as ^{R 1} and R ^2a.
Further, R ¹ and R ² may be combined to exhibit an alkylidene group (preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms).

L ^1a represents an alkylene group, an alkenylene group, an arylene group, -O- or -NR ^a - preferably showing a an alkylene group, an arylene group, or -NR ^a - is more preferable to indicate, that an alkylene group further preferable.

Y ^1a preferably represents an alkoxy group.
Y ^2a and Y ^3a preferably show a hydroxy group, an alkoxy group or an alkyl group, and more preferably show an alkoxy group or an alkyl group.

The ^{alkylene group that can be taken as L 1a} may be linear, branched or cyclic. The number of carbon atoms of the alkylene group is preferably 1 to 30, more preferably 1 to 25, more preferably 1 to 20, and even more preferably 1 to 15. Specific examples of the alkylene group include methylene, ethylene, propylene, tert-butylene, pentylene, cyclohexylene, heptylene, octylene, nonylene, decylene and undecylen.

The alkenylene group that can be taken as ^{L 1a may be either linear or branched.} The number of carbon atoms of the alkenylene group is preferably 2 to 20, more preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 6. Specific examples of the alkenylene group include ethenylene and propenylene.

The alkynylene group that can be taken as ^{L 1a may be either linear or branched.} The number of carbon atoms of the alkynylene group is preferably 2 to 20, more preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 6. Specific examples of the alkynylene group include ethynylene and propinylene.

The ^{number of carbon atoms of the arylene group that can be obtained as L 1a} is preferably 6 to 20, more preferably 6 to 15, more preferably 6 to 12, and even more preferably 6 to 10. Specific examples of the arylene group include phenylene and naphthylene.

-NR ^a - substituent can take as ^{R a} of an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms), an alkenyl group (preferably 2 to 12 carbon atoms, more preferably carbon Numbers 2-8), alkynyl groups (preferably 2-12 carbons, more preferably 2-8 carbons), aryl groups (preferably 6-20 carbons, more preferably 6-10 carbons) and heterocycles. The group is mentioned. The ^{heterocycle constituting the heterocyclic group that can be taken as Ra} may be a saturated or unsaturated aliphatic heterocycle or an aromatic heterocycle, and may be a monocyclic ring or a condensed ring. It may also be a bridge ring. Examples of the hetero atom contained in the heterocycle include an oxygen atom, a nitrogen atom and a sulfur atom. The number of heteroatoms contained in one heterocycle is not particularly limited, but is preferably 1 to 3, and more preferably 1 or 2. The heterocycle preferably has 2 to 10 carbon atoms, more preferably 4 or 5 carbon atoms. The heterocycle is preferably a 3- to 7-membered ring, more preferably a 3- to 6-membered ring, and even more preferably a 3- to 5-membered ring. Specific examples of the heterocycle include an epoxy ring, a 3,4-epoxycyclohexane ring, a furan ring and a thiophene ring.
Examples of -NR ^a- include -NH-.

Can take as L ^1a, the group or made by combining the coupling of two or more divalent group (hereinafter, also referred to as "group formed in combination can be taken as L ^1a".) Constituting, or linking combined The number of is preferably 2 to 8, more preferably 2 to 6, and even more preferably 2 to 4.
The molecular weight of the combined group that can be taken as L ^1a is preferably 20 to 1000, more preferably 30 to 500, and even more preferably 40 to 200.
Examples of the combined group that can be taken as L ^1a include urea bond, thiourea bond, carbamate group, sulfonamide bond, arylene-alkylene, -O-alkylene, amide bond-alkylene, -S-alkylene, alkylene-O. -Amid bond-alkylene, alkylene-amide bond-alkylene, alkenylene-amide bond-alkylene, alkylene-ester bond-alkylene, arylene-ester bond-alkylene,-(alkylene-O)-, alkylene-O- (alkylene-O) )-Alkylene (“(alkylene-O)” is a repeating unit), arylene-sulfonyl-O-alkylene and ester bond-alkylene.

The ^{alkyl group constituting the alkoxy group that can be taken as Y 1a} to Y ^3a may be linear, branched or cyclic, and may have a combination of these forms. In the present invention, the alkyl group is preferably a straight chain alkyl group. The number of carbon atoms of the alkyl group constituting the alkoxy group is preferably 1 to 15, more preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 or 2. Specific examples of the alkyl group constituting the alkoxy group include methyl, ethyl, propyl, t-butyl, pentyl and cyclohexyl.

Examples of the alkyl group that can be taken as Y ^2a and Y ^3a include an alkyl group that constitutes an alkoxy group that can be taken as ^{Y 1a} to Y ^3a , and a preferred form also constitutes an alkoxy group that can be taken as ^{Y 1a} to Y ^3a. It is the same as the preferred form of the alkyl group.

The ^{ketooxime group that can be obtained as Y 2a} and Y ^3a is a substituent having the following structure.

In the above structure, R ¹¹ and R ¹² indicate a substituent, and * indicates a bond to a silicon atom.
Examples of the substituent group R ¹¹ and R ¹² can take, and a substituted group in the R ^a, the same as the preferred form of the substituent which may take the preferred form as R ^a.

Examples of the ketooxime group include a dimethyl keto oxime group, a methyl ethyl keto oxime group, a diethyl keto oxime group and the like.

Hereinafter, specific examples of the aminosilane compound used in the present invention will be given, but the present invention is not limited thereto.
3-Aminopropyltrimethoxysilane 3-Aminopropyldimethylmethoxysilane 3-Aminopropylmethyldimethoxysilane 3-Aminopropylmethyldiethoxysilane 3-Aminopropyltriethoxysilane N- (2-aminoethyl) -3-aminopropylmethyl Dimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldiethoxysilane N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropyltriethoxy Silane3-methyldimethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine 3-methyldiethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine 3-trimethoxysilyl-N- (1) , 3-Dimethyl-butylidene) propylamine 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine N-phenyl-3-aminopropylmethyldiethoxysilane N-phenyl-3-aminopropylmethyldi Ethoxysilane N-phenyl-3-aminopropyltrimethoxysilane N-phenyl-3-aminopropyltriethoxysilane N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane

(Mercaptosilane compound)
The mercaptosilane compound (silane compound having a mercapto group (sulfanyl group)) is preferably a silane coupling agent having a mercapto group. The tungsten carbide particles surface-treated with the mercaptosilane compound preferably have a mercapto group derived from the mercaptosilane compound.

The mercaptosilane compound preferably contains at least one compound represented by the following general formula (B).

L ^1b , Y ^1b , Y ^2b and Y ^3b ^{are synonymous with L 1a} , Y ^1a , Y ^2a and Y ^3a of the above general formula (A), respectively, and the preferable ranges are also the same.

Hereinafter, specific examples of the mercaptosilane compound used in the present invention will be given, but the present invention is not limited thereto.
3-Mercaptopropyltrimethoxysilane 3-Mercaptopropyltriethoxysilane 3-Mercaptopropylmethyldimethoxysilane Mercaptomethylmethyldiethoxysilane (mercaptomethyl) Methyldimethoxysilane (mercaptomethyl) dimethylethoxysilane11-mercaptoundecyltrimethoxysilane

(Isocyanatosilane compound)
The isocyanatosilane compound (preferably a silane compound having an isocyanate group) is preferably a silane coupling agent having an isocyanate group. The tungsten carbide particles surface-treated with the isocyanate silane compound preferably have an isocyanate group derived from the isocyanate silane compound.

The isocyanatosilane compound preferably contains at least one compound represented by the following general formula (C).

L ^1c , Y ^1c , Y ^2c and Y ^3c ^{are synonymous with L 1a} , Y ^1a , Y ^2a and Y ^3a of the above general formula (A), respectively, and the preferable ranges are also the same.

Further, in the present invention, as the isocyanatosilane compound, it is also preferable to use a condensate of the compound represented by the general formula (C) and a compound in which the isocyanato group of the general formula (C) is protected by a substituent. .. The above substituents can be introduced by, for example, alcohol compounds, phenol compounds, aromatic amines, lactams and oximes. Examples of such an alcohol compound include alkyl alcohols (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms). Examples of the phenol compound include phenol and cresol. Further, as the lactam, for example, ε-caprolactam can be mentioned.
The "compound in which the isocyanate group of the general formula (C) is protected by a substituent" is a compound in which -NCO of the general formula (C) is replaced ^{with -NHC (= O) OR 4.} R ⁴ represents a substituent, and examples thereof include an alkyl group (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms).

Hereinafter, specific examples of the isocyanate compound used in the present invention will be given, but the present invention is not limited thereto.
3-Isocyanatopropyltrimethoxysilane 3-Isocyanatopropyltriethoxysilane Isocyanatomethyltrimethoxysilane (hereinafter, isocyanatosilane compound protected by condensation or substituent)
Tris (3-Trimethoxysilylpropyl) Isocyanurate (3-Triethoxysilylpropyl) -t-Butyl Carbamate Triethoxysilylpropyl Ethyl Carbamate

(Thiocyanatosilane compound)
The thiocyanatosilane compound (silane compound having a thiocyanato group) is preferably a silane coupling agent having a thiocyanato group. The tungsten carbide particles surface-treated with the thiocyanatosilane compound preferably have a thiocyanato group derived from the thiocyanatosilane compound.

The thiocyanatosilane compound preferably contains at least one compound represented by the following general formula (D).

L ^1d , Y ^1d , Y ^2d and Y ^3d ^{are synonymous with L 1a} , Y ^1a , Y ^2a and Y ^3a of the above general formula (A), respectively, and the preferable ranges are also the same.

Hereinafter, specific examples of the thiocyanatosilane compound used in the present invention will be given, but the present invention is not limited thereto.
3-Thiocyanatopropyltrimethoxysilane 3-Thiocyanatopropyltriethoxysilane Thiocyanatomethyltrimethoxysilane

(Aluminum alkoxide compound)
The aluminum alkoxide compound preferably contains at least one of an acetonato structure and an acetylate structure.

The aluminum alkoxide compound preferably contains at least one of the compounds represented by the following general formula (1).

General formula (1): R ^1a _m1- Al- (OR ^2a ) _3-m1

R ^1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
The ^{alkyl group that can be taken as R 1a} includes a linear alkyl group, a branched alkyl group, and an aralkyl group. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, further preferably 1 to 10 carbon atoms, particularly preferably 1 to 8 carbon atoms, and preferably 7 to 30 carbon atoms in the case of an aralkyl group. Preferred specific examples of this alkyl group include, for example, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, decyl, tridecyl, octadecyl, benzyl, and phenethyl. Can be mentioned.
It is also preferable that the alkyl group that can be taken as R ^{1a has an oxylan ring.} The number of ring members of the cycloalkyl group (cycloalkyl group having a structure in which an oxylan ring is condensed) in the epoxy cycloalkylalkyl group that can be taken as ^{R 1a is preferably 4 to 8, more preferably 5 or 6, and 6 (that is, epoxy).} Being a cyclohexyl group) is more preferred.
Further, the ^{alkyl group that can be taken as R 1a} preferably has a group selected from an amino group, an isocyanato group, a mercapto group, an ethylenically unsaturated group, and an acid anhydride group.

The ^{cycloalkyl group that can be taken as R 1a} preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, further preferably 3 to 10 carbon atoms, and particularly preferably 3 to 8 carbon atoms. Preferred specific examples of this cycloalkyl group include, for example, cyclopropyl, cyclopentyl, and cyclohexyl.

The ^{acyl group that can be obtained as R 1a} preferably has 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, further preferably 2 to 20 carbon atoms, and particularly preferably 2 to 18 carbon atoms.

The ^{aryl group that can be taken as R 1a} preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, further preferably 6 to 12 carbon atoms, and particularly preferably 6 to 10 carbon atoms. Preferred specific examples of this aryl group include, for example, phenyl and naphthyl, with phenyl being even more preferred.

The ^{unsaturated aliphatic group that can be obtained as R 1a} preferably has 1 to 5 carbon-carbon unsaturated bonds, more preferably 1 to 3, further preferably 1 or 2, and particularly preferably 1. preferable. The unsaturated aliphatic group may contain a heteroatom, and is preferably a hydrocarbon group. When the unsaturated aliphatic group is a hydrocarbon group, the number of carbon atoms is preferably 2 to 20, more preferably 2 to 15, further preferably 2 to 10, further preferably 2 to 8, and preferably 2 to 5. .. The unsaturated aliphatic group is more preferably an alkenyl group or an alkynyl group.

R ^1a is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, and more preferably an alkyl group or a cycloalkyl group.
When the compound of the general formula (1) has two or more ^{R 1a} ^{, the two R 1a} may be connected to each other to form a ring.

R ^2a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group (phosphonic acid group), or _-SO 2 ^{R S1.} ^RS1 represents a substituent.
The alkyl group, cycloalkyl group, acyl group, and aryl group that can be taken as ^{R 2a} are synonymous with the alkyl group, cycloalkyl group, acyl group, and aryl group that can be taken as ^{R 1a, respectively, and the preferred forms of each group.} Is the same. Further, the ^{alkyl group that can be taken as R 2a} preferably has an amino group as a substituent.

The ^{alkenyl group that can be taken as R 2a} includes a linear alkenyl group and a branched alkenyl group. The alkenyl group preferably has 2 to 18 carbon atoms, more preferably 2 to 7 carbon atoms, and even more preferably 2 to 5 carbon atoms. Preferred specific examples of this alkenyl group include, for example, vinyl, allyl, butenyl, pentenyl and hexenyl. The alkenyl group is preferably a substituted alkenyl group.

The ^{phosphonate group that can be taken as R 2a} is a group represented by −P (= O) (−OR ^P1 ) OR ^P2 . ^RP1 and ^RP2 represent a hydrogen atom or a substituent, and the substituent is preferably an alkyl group or a phosphonate group. The alkyl group that can be taken as ^{R P1} and R ^P2 ^{is synonymous with the alkyl group that can be taken as R 1a} described above, and the preferred form of the alkyl group is also the same. Phosphonate group, which may take as R ^P1 and ^{R P2} ^are the same as the phosphonate group can take as ^{R 2a,} a preferred form also the same. When R ^P1 or ^{R P2} is a phosphonate group, ^{R P1} and ^{R P2} constituting the phosphonate group is preferably an alkyl group.
As the phosphonate group that can be taken as ^{R 2a} ^{, it is preferable that both RP1} and ^RP2 are alkyl groups, or ^RP1 is a hydrogen atom and ^RP2 is a phosphonate group.
Since the phosphonate group is tautomerized with the phosphite group (phosphorous acid group), the phosphonate group in the present invention means to include the phosphite group.

In _{-SO 2} R ^S1 which can be taken as ^{R 2a} , an alkyl group or an aryl group is preferable as the substituent R ^S1. Preferred embodiments of the alkyl group and an aryl group which may take as R ^S1, respectively, may be mentioned preferred form of the alkyl and aryl groups which can be taken as R ^1a described above. Of these R ^S1 is phenyl having as a substituent an alkyl group is preferable. The preferred form of this alkyl group is the same as the preferred form of the alkyl group that can be taken as ^{R 1a described above.}

When the compound represented by the general formula (1) has two or more ^{R 2a} ^{, the two R 2a} may be connected to each other to form a ring.

M1 is an integer of 0 to 2.

In the above general formula (1), it is preferable that at least one of ^{OR 2a has an acetonato structure.} This acetnat structure means a structure in which one hydrogen ion is removed from a compound having a structure in which acetone or acetone has a substituent and is coordinated with Al. The coordination atom coordinated to Al is usually an oxygen atom. This acetonato structure is based on an acetylacetone structure (“CH _3- C (= O) -CH _2- C (= O) -CH ₃ ”), from which one hydrogen ion is removed to remove oxygen atoms. A structure coordinated to Al as a coordinating atom (that is, an acetylacetonato structure) is preferable. The above-mentioned "having an acetylacetone structure as a basic structure" means that, in addition to the above-mentioned acetylacetone structure, a structure in which a hydrogen atom of the above-mentioned acetylacetone structure is substituted with a substituent is included. Examples of the form in which OR ^2a has an acetonato structure include compounds SL-2 and SL-3, which will be described later.
In the above general formula (1), it is preferable that at least one of ^{OR 2a has an acetato structure.} In the present invention, the acetato structure is obtained by removing one hydrogen ion from acetic acid or acetic acid ester or a compound having a substituent (including a form in which the methyl group of acetic acid has an alkyl group as a substituent). It means a structure coordinated with. The coordination atom coordinated to Al is usually an oxygen atom. This acetato structure is an alkylacetate acetate structure (“CH _3- C (= O) -CH _2- C (= O) _{-OR alk} ” (R _alk is an alkyl group (preferably having 1 to 20 carbon atoms). It is an alkyl group, which may be an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms.))) As a basic structure, and hydrogen is obtained from the alkyl group. A structure in which one ion is removed and an oxygen atom is used as a coordinating atom to coordinate Al (that is, an alkylacetacetate structure) is preferable. The above-mentioned "using an alkylacetacetate structure as a basic structure" means that, in addition to the above-mentioned alkylacetate-acetate structure, a structure in which a hydrogen atom of the above-mentioned alkylacetate-acetate structure is substituted with a substituent is included. Examples of the form in which OR ^2a has an acetato structure include compounds SL-3, SL-4, and SL-5, which will be described later.

Each group that can be taken as R ^1a or R ^2a may have an anionic group having a counter cation (salt-type substituent) as a substituent. The anionic group means a group capable of forming an anion. Examples of the anionic group having a counter cation include a carboxylic acid ion group having an ammonium ion as a counter cation. In this case, the counter cation may be present in the compound represented by the above general formula (1) so that the charge of the entire compound becomes zero. This also applies to the compound represented by the general formula (2) and the compound represented by the general formula (3), which will be described later.

Hereinafter, specific examples of the aluminum alkoxide compound used in the present invention will be given, but the present invention is not limited thereto.
Aluminum Trietilate Aluminum Triisopropoxide Aluminum Trisec-Butylate Aluminum Tris (Ethylacetacetate)
Ethyl Acetylacetone Aluminum Diisopropilate Aluminum Monoacetylacetone Bis (Ethylacetone Acetate)
Aluminum tris (acetylacetone)
Diisopropoxyaluminum-9-octadecenylacetate aluminum diisopropoxymonoethylacetate aluminum trisethylacetate aluminum trisacetylacetonate monosec-butoxyaluminum diisopropirate ethylacetacetate aluminum diisopropylatediethylacetate aluminum Isopropylate Aluminum Bisethylacetate Monoacetylacetate Aluminum Trisethylacetate Aluminum Octadecylacetate Diisopropylate

(Zirconium alkoxide compound)
The zirconium alkoxide compound preferably contains at least one of an acetonate structure, an acetylate structure and a lactoto structure, and more preferably contains at least one of an acetonato structure and an acetylate structure.

The zirconium alkoxide compound preferably contains at least one of the compounds represented by the following general formula (2).

General formula (2): R ^1b _m2- Zr- (OR ^2b ) _4-m2

R ^1b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
As an alkyl group, a cycloalkyl group, an acyl group, an aryl group and an unsaturated aliphatic group, for example, an alkyl group, a cycloalkyl group, an acyl group, an aryl group and an unsaturated fatty group which can be taken as ^{R 1a of the above general formula (1).} A family group can be adopted.

R ^2b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or _-SO 2 ^{R S2.} ^RS2 indicates a substituent.
As an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group and a phosphonate group, for example, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, which can be taken as ^{R 2a of the above general formula (1),} A phosphonate group can be adopted. Further, as the substituent which can be taken as R ^S2, for example, it can be adopted a substituent which can be taken as R ^S1 of the general formula (1).

M2 is an integer from 0 to 3.

In the above general formula (2), it is preferable that at least one of ^{OR 2b has an acetonato structure.} This acetonato structure is synonymous with the acetonato structure described by the general formula (1). Examples of the form in which OR ^2b has an acetonato structure include compounds SZ-3 and SZ-6, which will be described later.
Further, in the above general formula (2), it is preferable that at least one of ^{OR 2b has an acetato structure.} This acetato structure is synonymous with the acetato structure described by the general formula (1). Examples of the form in which OR ^2b has an acetato structure include SZ-7, which will be described later. The compound SZ-5 corresponds to the form in which ^{R 2b} is an acyl group in the general formula (1).
Further, in the above general formula (2), it is preferable that at least one of ^{OR 2b has a lacto structure.} This lactato structure means a structure in which a lactic acid ion (lactoto) is used as a basic structure, and one hydrogen ion is removed from the basic structure to coordinate to Zr. The above-mentioned "having a lactic acid ion as a basic structure" means that, in addition to the above-mentioned lactic acid ion, a structure in which a hydrogen atom of the above-mentioned lactic acid ion is substituted with a substituent is included. The coordination atom coordinated to this Zr is usually an oxygen atom. Examples of the form in which OR ^2b has a lacto structure include the compound SZ-4 described later.

Hereinafter, specific examples of the zirconium alkoxide compound used in the present invention will be given, but the present invention is not limited thereto.
Tetrapropoxyzirconium (also known as zirconium tetra n-propoxide)
Tetrabutoxyzirconium (also known as zirconium tetra n-butoxide)
Zirconium Tetra Acetylacetone Zirconium Tributoxy Monoacetylacetone Zirconium Dibutoxybis (Acetylacetoneate)
Zirconium dibutoxybis (ethylacetate acetate)
Zirconium Tributoxyethyl Acetyl Acetate Zirconium Monobutoxy Acetylacetone Bis (Ethyl Acet Acetate)
Zirconium tributoxymonostearate (also known as zirconium stearate n-butoxide)
Zirconium stearate Zirconium lactate ammonium salt zirconium monoacetylacetone

(Titanium alkoxide compound)
The titanium alkoxide compound preferably contains at least one atom of N, P and S. It is also preferable that the titanium alkoxide compound has an acetato structure.

The titanium alkoxide compound preferably contains at least one of the compounds represented by the following general formula (3).

General formula (3): R ^1c _m3- Ti- (OR ^2c ) _4-m3

R ^1c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
As an alkyl group, a cycloalkyl group, an acyl group, an aryl group and an unsaturated aliphatic group, for example, an alkyl group, a cycloalkyl group, an acyl group, an aryl group and an unsaturated fatty group which can be taken as ^{R 1a of the above general formula (1).} A family group can be adopted.

R ^2c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or _-SO 2 ^{R S3.} ^RS3 indicates a substituent.
As an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group and a phosphonate group, for example, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, which can be taken as ^{R 2a of the above general formula (1),} A phosphonate group can be adopted. Further, as the substituent which can be taken as R ^S3, for example, it can be adopted a substituent which can be taken as R ^S1 of the general formula (1).

M3 is an integer from 0 to 3.

The compound represented by the above general formula (3) preferably contains at least one atom of N, P and S. When the compound represented by the general formula (3) has N, it is preferable to have this N as an amino group.
When the compound represented by the general formula (3) has P, it is preferable to have this P as a phosphate group (phosphoric acid group) or a phosphonate group (phosphonic acid group).
When the compound represented by the general formula (3) has S, it is preferable _{to have this S as a sulfonyl group (-SO 2-).}
Further, it is also preferable that the compound represented by the above general formula (3) ^{has an acyl group as R 2c} , that is, has the above-mentioned acetate structure as ^{OR 2c.}

Hereinafter, specific examples of the zirconium alkoxide compound used in the present invention will be given, but the present invention is not limited thereto.
Isopropyltriisostearoyl titanate Isopropyltridodecylbenzenesulfonyl titanate Isopropyltrioctanoyl titanate Isopropyltri (dioctylphosphate) Titanate Isopropyltris (dioctylpyrophosphate) Titanate Isopropyltri (dioctylsulfate) Titanate Isopropyltricumylphenyl titanate Isopropyltri (N- Aminoethyl-aminoethyl) titanate isopropyl dimethacryl isostearoyl titanate isopropyl isostearoyl diacrylic titanate isobutyltrimethyl titanate diisostearoyl ethylene titanate diisopropylbis (dioctylpyrophosphate) titanate dioctylbis (ditridecylphosphate) titanate dicumylphenyloxyacetate titanate bis (Dioctyl Pyrophosphate) Oxyacetate Titanate Bis (Dioctyl Pyrophosphate) Ethyl Titanate Bis (Dioctyl Pyrophosphate) Oxyacetate Titanate Tetraisopropyl Titanate Tetrabutyl Titanate Tetraoctyl Titanate Tetrastearyl Titanate Tetraisopropylbis (Dioctyl Phosphite) Titanate Tetraoctylbis (Dioctyl Phosphite) Di-tridecylphosphite) titanate tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate butyl titanate dimer titanium tetraacetylacetonate titanium ethylacetate acetate titanium octylene glycolate titanium di -2-Ethylhexoxybis (2-ethyl-3-hydroxyhexoxide)

The mass ratio of the tungsten carbide particles to the surface treatment agent in the component (C) is not particularly limited, and for example, the surface treatment agent is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the tungsten carbide particles. It is more preferably 1 to 80 parts by mass, and more preferably 1 to 50 parts by mass from the viewpoint of suppressing the decrease in sound velocity of the acoustic matching sheet and reducing the variation in the acoustic characteristics of the acoustic matching sheet. It is more preferably parts by mass, and even more preferably 10 to 50 parts by mass.
The mass ratio of the tungsten carbide particles in the component (C) to the surface treatment agent is synonymous with the mass ratio of the amount of the tungsten carbide particles used in the surface treatment to the surface treatment agent. The mass ratio of the tungsten carbide particles in the component (C) to the surface treatment agent is such that the organic component is removed by heating the component (C) to 500 ° C. or higher by thermal mass measurement (TGA) or the like to remove the inorganic component (tungsten). Carbide particles) can be obtained and calculated from the mass of the tungsten carbide particles and the mass of the component (C).

A surface treatment agent other than the above-mentioned surface treatment agent may be used as long as the effect of the present invention is not impaired.

The surface treatment method itself can be carried out by a conventional method.
As for the component (C), it is not necessary that the entire surface of the tungsten carbide particles is treated with a surface treatment agent, and for example, it is preferable that 50% or more of the surface area of the tungsten carbide particles is surface-treated. 70% or more is more preferable, and 90% or more is further preferable.
The component (C) may be used alone or in combination of two or more.
Of the total content of each of the components (A) to (C) of 100 parts by mass, the content of the component (C) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more from the viewpoint of further increasing the acoustic impedance. , 80 parts by mass or more is more preferable, and 90 parts by mass or more is further preferable. Further, out of a total of 100 parts by mass of each content of the components (A) to (C), the content of the component (C) is preferably 98 parts by mass or less, more preferably 95 parts by mass or less, and further preferably 94 parts by mass or less. preferable. By setting the content of the component (C) to 90 parts by mass or more and 94 parts by mass or less, variations in acoustic characteristics can be effectively suppressed.
Further, the contents of the components (A) and (B) in 100 parts by mass of the total contents of the components (A) to (C) are preferably in the following range.
The content of the component (A) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 4 parts by mass or more. Further, 10 parts by mass or less is preferable, 9 parts by mass or less is more preferable, and 8 parts by mass or less is further preferable.
The content of the component (B) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and further preferably 0.14 parts by mass or more. Further, 4 parts by mass or less is preferable, 3 parts by mass or less is more preferable, and 2.5 parts by mass or less is further preferable.
The content ratio of the component (A) to the component (B) may be appropriately adjusted according to the type of the component (B) to be used and the like. For example, in terms of mass ratio, component (A) / component (B) = 99/1 to 20/80, preferably 90/1 to 40/60, and even more preferably 90/1 to 75/25.

<Surface modification process>
Further, from the viewpoint of suppressing the decrease in sound velocity of the acoustic matching sheet and reducing the variation in the acoustic characteristics of the acoustic matching sheet, before the surface-treated tungsten carbide particles used in the present invention are surface-treated with the above-mentioned surface treatment agent. , Tungsten carbide particles may be surface-modified by contacting the tungsten carbide particles with an oxidizing agent in an aqueous solution.
The surface modification step is a step of bringing the tungsten carbide particles into contact with an oxidizing agent in an aqueous solution to obtain modified tungsten carbide particles.
The pH of the aqueous solution is, for example, more than 7, preferably 10 or more, more preferably 12 or more, further preferably more than 12, particularly preferably 13 or more, and most preferably more than 13.
The upper limit of the pH of the aqueous solution is not limited, and is, for example, 14 or less.
The pH of the aqueous solution means the pH of the aqueous solution in a state containing the tungsten carbide particles and the oxidizing agent. That is, the aqueous solution contains at least water, tungsten carbide particles, and an oxidizing agent.
The time for contacting the tungsten carbide particles with the oxidizing agent in the above aqueous solution is preferably 0.1 to 24 hours, more preferably 0.5 to 10 hours, and even more preferably 1.5 to 6 hours.
The temperature of the aqueous solution when the tungsten carbide particles are brought into contact with the oxidizing agent is preferably 1 to 95 ° C, more preferably 25 to 80 ° C, and even more preferably 45 to 65 ° C.
There is no limitation on the method of contacting the tungsten carbide particles with the oxidizing agent in the above aqueous solution, and for example, a crusher or a crusher such as a locking mill, a piece mill, a ball mill, a henschel mixer, a jet mill, a stirrer, or a paint conditioner. A method of mixing and contacting by a treatment using, a method of contacting while stirring using a mechanical stirrer such as a three-one motor or a magnetic stirrer, and an oxidation containing an oxidizing agent or the like in a cartridge filled with tungsten carbide particles. An example is a method in which the aqueous agent is circulated by a pump and brought into contact with each other.
Further, as a method of bringing the tungsten carbide particles into contact with the oxidizing agent in the aqueous solution, a method may be selected in which the tungsten carbide particles or the modified tungsten carbide particles are not destroyed as much as possible in the aqueous solution. The term "destruction" as used herein means, for example, that when the tungsten carbide particles to be treated are agglomerated tungsten carbide particles, the agglomerated form is destroyed.
It is preferable that the tungsten carbide particles and the oxidizing agent are brought into contact with each other in the aqueous solution, and then the obtained modified tungsten carbide particles are taken out from the aqueous solution.
There is no limitation on the method of extracting the modified tungsten carbide particles from the aqueous solution, and examples thereof include a method of filtering the aqueous solution and separating (filtering) the modified tungsten carbide particles as a filter medium.
It is also preferable to wash the removed modified tungsten carbide particles with water and / or an organic solvent or the like.
(Oxidant)
The aqueous solution contains an oxidizing agent.
There are no restrictions on the oxidizing agent, for example, persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; nitrates such as cerium ammonium nitrate, sodium nitrate, and ammonium nitrate; hydrogen peroxide, and tert. -Peroxides such as butyl hydroperoxide; permanganates such as potassium permanganate; divalent copper compounds and transition metal compounds; potassium permanganate and super such as sodium permanganate Atomic iodine compounds; quinone compounds such as benzoquinone, naphthoquinone, anthraquinone, and chloranyl; and salts of sodium hypochlorite and halogen oxo acids such as sodium chlorite.
Among them, the oxidizing agent preferably contains a persulfate, and more preferably a persulfate.
Further, in order to assist the action of the oxidant, a catalyst may be used separately from the oxidant. Examples of the catalyst include a divalent iron compound (FeSO _4, etc.) and a trivalent iron compound.
The oxidizing agent and / or the catalyst may be a hydrate.
Further, the standard oxidation-reduction potential of the oxidizing agent is preferably 0.30 V or more, more preferably 1.50 V or more, and further preferably 1.70 or more. There is no limit to the upper limit of the standard redox potential of the oxidizing agent, for example, it is preferably 4.00 V or less, and more preferably 2.50 V or less.
The standard redox potential is based on the standard hydrogen electrode.
The content of the oxidizing agent in the aqueous solution is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, and further preferably 1 to 20 parts by mass with respect to 100 parts by mass of water in the aqueous solution. preferable.
The oxidizing agent may be used alone or in combination of two or more.
When the aqueous solution contains a catalyst, the content thereof is preferably 0.005 to 2 parts by mass, more preferably 0.01 to 2 parts by mass, and 0.1 to 2 parts by mass with respect to 100 parts by mass of water in the aqueous solution. Parts by mass are more preferred.
The content of the catalyst in the aqueous solution is preferably 0.1 to 80 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the oxidizing agent in the aqueous solution.
The catalyst may be used alone or in combination of two or more.
The amount of the oxidizing agent to be brought into contact with the tungsten carbide particles is preferably 0.1 to 1000 parts by mass, more preferably 1 to 250 parts by mass, and 15 to 120 parts by mass with respect to 100 parts by mass of the tungsten carbide particles. More preferred.
(Alkaline source)
The aqueous solution preferably contains an alkaline source in addition to the above components in order to adjust the pH of the aqueous solution.
Examples of the alkali source include alkali metal hydroxides (sodium hydroxide and the like), inorganic bases such as alkaline earth metal hydroxides; and organic bases.
The content of the alkali source in the aqueous solution may be appropriately adjusted so that the pH of the aqueous solution can be adjusted to a desired temperature. For example, 0.1 to 10 parts by mass with respect to 100 parts by mass of water in the aqueous solution. Is.

<Other ingredients>
In addition to the components (A) to (C), examples of the material of the present invention include curing retarders, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, and thermal conductivity improvers. ..

<Preparation of materials for acoustic matching layer>
When the material of the present invention is in the form of a composition for an acoustic matching layer formed by mixing the components (A) to (C), the mixing method is not particularly limited as long as each component can be substantially uniformly mixed. For example, the desired uniform mixing can be achieved by kneading using a rotation / revolution stirrer. By curing this mixture while molding it, an acoustic matching sheet or a precursor thereof can be prepared.

Further, the material of the present invention is, for example, a set for an acoustic matching layer containing a main agent containing the component (A) and the component (C) and a curing agent for the component (B) (referred to as the above-mentioned form (ii)). In the case of the form of, the main agent can be obtained by mixing the component (A) and the component (C). At the time of producing the acoustic matching sheet, the acoustic matching sheet or its precursor can be prepared by mixing the main agent and the curing agent, molding and curing the mixture.

[Acoustic matching sheet (acoustic matching layer)]
The acoustic matching sheet of the present invention can be obtained by molding a mixture of the above components, curing the mixture, and then cutting, dicing, or the like to a desired thickness or shape, if necessary. Further, the acoustic matching sheet can be further processed into a desired shape by a conventional method.
Specifically, for example, the material of the present invention is molded into a desired sheet shape in a low temperature region where a curing reaction does not occur or in a low temperature region where the curing rate is sufficiently slow. Then, if necessary, it is cured by heating or the like to obtain a cured product, and this cured product is cut or diced to a desired thickness or shape as necessary to obtain an acoustic matching sheet. That is, the acoustic matching sheet to be formed is preferably a cured product obtained by curing a mixture of the components constituting the material of the present invention. This acoustic matching sheet is used as an acoustic matching layer of the acoustic wave probe. The configuration of the acoustic wave probe including the acoustic matching layer will be described later.

[Acoustic wave probe]
The acoustic wave probe of the present invention has the acoustic matching sheet of the present invention as at least one layer of the acoustic matching layer.
An example of the configuration of the acoustic wave probe of the present invention is shown in FIG. The acoustic wave probe shown in FIG. 1 is an ultrasonic probe in an ultrasonic diagnostic apparatus. The ultrasonic probe is a probe that uses ultrasonic waves as an acoustic wave in the acoustic wave probe. Therefore, the basic structure of the ultrasonic probe can be applied as it is to the acoustic wave probe.

<Ultrasonic probe>
The ultrasonic probe 10 is a main component of an ultrasonic diagnostic apparatus, and has a function of generating ultrasonic waves and transmitting and receiving an ultrasonic beam. As shown in FIG. 1, the structure of the ultrasonic probe 10 is provided in the order of the acoustic lens 1, the acoustic matching layer 2, the piezoelectric element layer 3, and the backing material 4 from the tip (the surface in contact with the living body to be inspected). ing. In recent years, for the purpose of receiving high-order harmonics, a transmitting ultrasonic vibrator (piezoelectric element) and a receiving ultrasonic vibrator (piezoelectric element) are made of different materials to form a laminated structure. Has also been proposed.

(Piezoelectric element layer)
The piezoelectric element layer 3 is a portion that generates ultrasonic waves, and electrodes are attached to both sides of the piezoelectric element, and when a voltage is applied, the piezoelectric element repeatedly expands and contracts and expands to vibrate, thereby generating ultrasonic waves. do.

The material constituting the piezoelectric element, _quartz, LiNbO 3, a single crystal such as LiTaO _3, and KNbO _3, thin film and Pb (Zr, Ti), such as ZnO and AlN sintered body such as _{O 3} system was polarized, So-called ceramic inorganic piezoelectric materials are widely used. Generally, piezoelectric ceramics such as PZT: lead zirconate titanate having high conversion efficiency are used.
Further, the piezoelectric element that detects the received wave on the high frequency side needs a sensitivity with a wider bandwidth. Therefore, as a piezoelectric element suitable for high frequency and wide band, an organic piezoelectric material using an organic polymer substance such as polyvinylidene fluoride (PVDF) is used.
Further, Japanese Patent Application Laid-Open No. 2011-071842 and the like utilize MEMS (Micro Electro Mechanical Systems) technology, which exhibits excellent short pulse characteristics and wideband characteristics, is excellent in mass productivity, and can obtain an array structure with little variation in characteristics. cMUT is described.
In the present invention, any piezoelectric element material can be preferably used.

(Backing material)
The backing material 4 is provided on the back surface of the piezoelectric element layer 3 and shortens the pulse width of the ultrasonic wave by suppressing excessive vibration, which contributes to the improvement of the distance resolution in the ultrasonic diagnostic image.

(Acoustic matching layer)
The acoustic matching layer 2 is provided in order to reduce the difference in acoustic impedance between the piezoelectric element layer 3 and the subject to be inspected and to efficiently transmit and receive ultrasonic waves.

(Acoustic lens)
The acoustic lens 1 is provided to focus ultrasonic waves in the slice direction by utilizing refraction and improve the resolution. In addition, the ultrasonic waves should be in close contact with the living body to be examined and matched with the acoustic impedance of the living body (1.4 to 1.7 Milly in the human body), and the amount of ultrasonic attenuation of the acoustic lens 1 itself should be small. Is required.
That is, as the material of the acoustic lens 1, the sound velocity is sufficiently smaller than the sound velocity of the human body, the attenuation of ultrasonic waves is small, and the acoustic impedance is close to the value of the skin of the human body, so that ultrasonic waves can be transmitted and received. Sensitivity is increased.

The operation of the ultrasonic probe 10 having such a configuration will be described. A voltage is applied to the electrodes provided on both sides of the piezoelectric element to resonate the piezoelectric element layer 3, and an ultrasonic signal is transmitted from the acoustic lens to the subject to be inspected. At the time of reception, the piezoelectric element layer 3 is vibrated by the reflected signal (echo signal) from the test object, and this vibration is electrically converted into a signal to obtain an image.

[Manufacturing of acoustic wave probe]
The acoustic wave probe of the present invention can be produced by a conventional method except that the material of the present invention is used. That is, the method for manufacturing an acoustic wave probe of the present invention includes forming an acoustic matching layer on the piezoelectric element side using the material of the present invention. The piezoelectric element can be provided on the backing material by a conventional method.
Further, an acoustic lens is formed on the acoustic matching layer by a conventional method using a material for forming the acoustic lens.

[Acoustic wave measuring device]
The acoustic wave measuring device of the present invention has the acoustic wave probe of the present invention. The acoustic wave measuring device has a function of displaying the signal strength of the signal received by the acoustic wave probe and imaging the signal.
It is also preferable that the acoustic wave measuring device of the present invention is an ultrasonic measuring device using an ultrasonic probe.

The present invention will be described in more detail below based on an example in which ultrasonic waves are used as acoustic waves. The present invention is not limited to ultrasonic waves, and an acoustic wave having an audible frequency may be used as long as an appropriate frequency is selected according to the test object, measurement conditions, and the like.

[Preparation Example] Preparation Example of Surface-treated Tungsten Carbide Particles (C-1) 3-Aminopropyltrimethoxysilane 3.0 parts by mass, methanol 100 parts by mass, distilled water 3.3 parts by mass, and then at 23 ° C. The mixture was allowed to stand for 1 hour to allow the hydrolysis of the methoxy group to proceed. 10.0 parts by mass of tungsten carbide particles (manufactured by A.L.M., trade name "WC60S", average primary particle diameter 6.5 μm) were added to this solution. Using a homogenizer (“ED-7 type auto-excel homogenizer” (trade name) manufactured by Nippon Seiki Co., Ltd.), the mixture is stirred at a rotation speed of 10,000 rpm for 60 minutes while cooling so that the liquid temperature does not exceed 50 ° C. Then, surface treatment was performed while crushing.
The mixture after stirring and pulverizing above is filtered off, and the obtained solid is heated and dried at 100 ° C. for 30 minutes to obtain powdery surface-treated tungsten carbide particles (C-1) (component (C)). rice field.
In the preparation of the surface-treated tungsten carbide particles (C-1), the surface-treated tungsten carbide particles (C-) were prepared in the same manner as the surface-treated tungsten carbide particles (C-1) except that the raw materials were used in the compositions shown in Table 1 below. 2)-(C-30) were prepared. Tables 1-1 to 1-6 below are collectively referred to as Table 1.
In the preparation of the surface-treated tungsten carbide particles (C-2) to (C-30), 10.0 parts by mass of the raw material tungsten carbide particles were used.
In the preparation of the surface-treated tungsten carbide particles (C-1), when tungsten particles were used instead of the tungsten carbide particles, the surface treatment could not be sufficiently performed and the particles were aggregated and could not be used.

[Preparation Example] Preparation Example of Surface-treated Tungsten Carbide Particles (C-31) Tungsten Carbide Particles (50 g) were added to NaOH water (NaOH: 40 g / water: 400 ml) and stirred. After further adding sodium persulfate water (sodium persulfate: 9.6 g / water: 100 ml) to the above NaOH water, the temperature of the above NaOH water was raised to 50 ° C., and the mixture was further stirred for 3 hours (denaturation step). A three-one motor manufactured by Shinto Kagaku Co., Ltd. was used for stirring, and the stirring was performed at 150 rpm.
After cooling the NaOH water to room temperature, the tungsten carbide particles in the NaOH water are collected by filtration, and the collected tungsten carbide particles are washed with water (500 ml) and acetonitrile (250 ml) to modify the tungsten carbide. Obtained particles.
Surface-treated tungsten carbide particles (C-1) were prepared in the same manner as the surface-treated tungsten carbide particles (C-1), except that modified tungsten carbide particles were used instead of the tungsten carbide particles. Particles (C-31) were prepared.
In the preparation of the surface-treated tungsten carbide particles (C-31), the surface-treated tungsten carbide particles (C-31) were prepared in the same manner as the surface-treated tungsten carbide particles (C-31) except that the raw materials were used in the compositions shown in Table 1 below. 32)-(C-48) were prepared.

<Note to table>
[Tungsten Carbide Particles (W)]
(W-1):
Untreated tungsten carbide particles (manufactured by A.L.M., trade name "WC30S", average primary particle size 3 μm)
(W-2):
Untreated Tungsten Carbide Particles (manufactured by A.L.M., trade name "WC60S", average primary particle size 6.5 μm)
(W-3):
Untreated Tungsten Carbide Particles (manufactured by A.L.M., trade name "WC80S", average primary particle size 9 μm)
(W-4):
Untreated Tungsten Carbide Particles (manufactured by A.L.M., trade name "WC100S", average primary particle size 15 μm)
[Surface treatment agent (S)]
<Aminosilane compound>
(SA-1):
3-Aminopropyltrimethoxysilane (manufactured by Gelest, trade name "SIA0611.0")
<Mercaptosilane compound>
(SM-1):
3-Mercaptopropyltrimethoxysilane (manufactured by Gelest, trade name "SIM6476.0")
(SM-2):
11-Mercaptoundecyltrimethoxysilane (manufactured by Gelest, trade name "SIM6480.0")
<Isocyanatosilane compound>
(SI-1):
3-Isocyanatopropyltrimethoxysilane (manufactured by Gelest, trade name "SII6456.0")
(SI-2):
Isocyanatomethyltrimethoxysilane (manufactured by Gelest, trade name "SII6453.8")

<Titanium alkoxide compound>
(ST-1):
Isopropyltriisostearoyl titanate (manufactured by Ajinomoto Fine-Techno), trade name "Plenact TTS"

(ST-2):
Dioctylvis (ditridecyl phosphate) titanate (Ajinomoto Fine Techno Co., Ltd. "Plenact 46B"

(ST-3):
Isopropyltri (N-aminoethyl-aminoethyl) titanate (manufactured by Ajinomoto Fine-Techno, trade name "Plenact 44")

<Aluminum alkoxide compound>
(SL-1):
Aluminum trisec-butyrate (manufactured by Kawaken Fine Chemicals, trade name "ASBD")

(SL-2):
Aluminum trisacetylacetone (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "Organix AL-3100")

(SL-3):
Aluminum Bisethylacetate Acetate Monoacetylacetone (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "Organix AL-3200")

(SL-4):
Aluminum Trisethylacetacetate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "Organix AL-3215")

(SL-5):
Aluminum octadecylacetacetate diisopropilate (manufactured by Ajinomoto Fine-Techno, trade name "Plenact AL-M")

<Zirconium alkoxide compound>
(SZ-1):
Zirconium Tetra n-Propoxide (manufactured by Matsumoto Fine Chemicals, trade name "Organics ZA-45")

(SZ-2):
Zirconium tetra n-butoxide (manufactured by Matsumoto Fine Chemicals, trade name "Organics ZA-65")

(SZ-3):
Zirconium tetraacetylacetone (manufactured by Matsumoto Fine Chemicals, trade name "Organix ZC-150")

(SZ-4):
Zirconium lactate ammonium salt (manufactured by Matsumoto Fine Chemicals, trade name "Organix ZC-300")

(SZ-5):
Zirconium stearate tributoxide (manufactured by Matsumoto Fine Chemicals, trade name "Organics ZC-320")

(SZ-6):
Zirconium tributoxymonoacetylacetone (manufactured by Matsumoto Fine Chemicals, trade name "Organix ZC-540")

(SZ-7):
Zirconium dibutoxybis (ethylacetacetate) (manufactured by Matsumoto Fine Chemicals, trade name "Organix ZC-580")

<Oxidizing agent>
Sodium persulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
Sodium hypochlorite (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

<Surface treatment agent used in the comparative example>
(SA-2):
N-Trimethoxysilylpropyl-N, N, N-trimethylammonium chloride (manufactured by Gelest, trade name "SIT8415.0", 50% aqueous methanol solution)
(SC-1):
Methyltrichlorosilane (SC-2):
Vinyltrichlorosilane (SC-3):
3-methacryloxypropyltrimethoxysilane

<1> Preparation of material for acoustic matching layer (1) Preparation of material for acoustic matching layer used in Example 1 Epoxy resin (component (A) in Table 1 below, bisphenol A diglycidyl ether ("jER825" manufactured by Mitsubishi Chemical Corporation) (Product name), epoxy equivalent 170)) 5.6 parts by mass, isofolone diamine (component (B) in Table 1 below) 1.4 parts by mass, surface-treated tungsten carbide particles (C-1) prepared in the above preparation example. (Component (C) in Table 1 below) 93 parts by mass was added to a cylindrical container with an internal space of 40 mm in diameter so that the thickness after mixing would be 3 mm, and a rotation / revolution device (trade name: ARV-). The material for the acoustic matching layer used in Example 1 was prepared by mixing with 310 (manufactured by Shinky Co., Ltd.).

(2) Preparation of material for acoustic matching layer used in Examples 2 to 60 and Comparative Examples 1 to 5 Preparation of material for acoustic matching layer used in Example 1 except that the composition is replaced with the composition shown in Table 1 below. In the same manner, the materials for the acoustic matching layer used in Examples 2 to 60 and Comparative Examples 1 to 5 were prepared.

<2> Preparation of Acoustic Matching Sheet (1) Preparation of Acoustic Matching Sheet of Example 1 After mixing the materials for the acoustic matching layer used in Example 1, the material for the acoustic matching layer used in Example 1 is kept in the above container at 80 ° C. for 18 hours, and then. A circular acoustic matching sheet having a diameter of 40 mm and a thickness of 3 mm was prepared by curing at 150 ° C. for 1 hour. This sheet was cut into three circular acoustic matching sheets having a diameter of 40 mm and a thickness of 1 mm with a dicer, and one acoustic matching sheet (thickness 1 mm) in the center was used in the test example described later.

(2) Preparation of Acoustic Matching Sheets of Examples 2 to 60 and Comparative Examples 1 to 5 The acoustic matching layer used in Examples 2 to 60 and Comparative Examples 1 to 5 instead of the material for the acoustic matching layer used in Example 1. An acoustic matching sheet (thickness 1 mm) was prepared in the same manner as the acoustic matching sheet used in Example 1 except that the material was used, and used in the test example described later.

<3> Preparation of reference acoustic matching sheet The reference acoustic matching sheet used in the following [Test Example 2] was prepared as follows.
(1) Preparation of Reference Acoustic Matching Sheet Used for Evaluation of Example 1 Instead of the material for the acoustic matching layer used in Example 1, epoxy resin (component (A) in Table 1 below, bisphenol A diglycidyl ether (Mitsubishi Chemical) Acoustic matching used in Example 1 except that 80 parts by mass of "jER825" (trade name) manufactured by the company, epoxy equivalent 170)) and 20 parts by mass of isophorone diamine (component (B) in Table 1 below) were used. A reference acoustic matching sheet (thickness 1 mm) used for the evaluation of Example 1 was prepared in the same manner as the sheet, and used in Test Example 2 described later.
(2) Preparation of Reference Acoustic Matching Sheet Used for Evaluation of Examples 2 to 60 and Comparative Examples 1 to 5 In the preparation of the reference acoustic matching sheet used in Example 1, the compounding ratio of the epoxy resin and the curing agent is shown in Table 1. The reference acoustic matching sheet used for the evaluation of Examples 2 to 60 and Comparative Examples 1 to 5 was prepared in the same manner as the preparation of the reference acoustic matching sheet used for the evaluation of Example 1 except that the compounding ratio was changed to. ..

[Test Example 1] Measurement of sound velocity The ultrasonic sound velocity is measured at 25 ° C. using a single-around sound velocity measuring device (manufactured by Ultrasonic Industry Co., Ltd., trade name "UVM-2 type") in accordance with JIS Z2353 (2003). bottom. With respect to the circular acoustic matching sheet having a diameter of 40 mm and a thickness of 1 mm obtained above, the entire inside of these three circular regions (small probe size of a single channel) is measured for three circular regions having a diameter of 1.5 cm that do not overlap each other. Targeted. The arithmetic mean value of the sound velocity in the above three circular regions was calculated, and the rate (%) of the sound velocity decrease obtained from the following formula was applied to the following evaluation criteria and evaluated. S to D pass this test. The results are shown in Table 2 below. In addition, the following Tables 2-1 to 2-7 are collectively referred to as Table 2.
Rate of decrease in sound velocity (%) = 100 × (Arithmetic mean value of sound velocity of reference acoustic matching sheet-Arithmetic mean value of sound velocity of acoustic matching sheet of Example or Comparative Example) / Arithmetic mean value of sound velocity of reference acoustic matching sheet
-Evaluation criteria-
S: Less than 5% A: 5% or more and less than 7% B: 7% or more and less than 9% C: 9% or more and less than 11% D: 11% or more and less than 13% E: 13% or more and less than 15% F: 15% or more

[Test Example 2] Variation in Acoustic Impedance (AI) A test piece of 10 mm × 10 mm was cut out from each sound velocity measurement target (circle with a diameter of 1.5 cm) of Test Example 1 above. The density of the test piece at 25 ° C. is measured by using an electronic hydrometer (manufactured by Alpha Mirage Co., Ltd., trade name "SD-200L") according to the density measurement method of method A (underwater substitution method) described in JIS K7112 (1999). Measured using. For the acoustic matching sheets of each example and comparative example, the acoustic impedance (density x sound velocity) was calculated for each of the three circular regions, the standard deviations of the three acoustic impedances were obtained, and the variations in acoustic characteristics were applied to the following evaluation criteria. Was evaluated. A to C pass this test. The results are shown in Table 2 below.
-Evaluation criteria-
A: Less than 0.5Mrayl B: 0.5Mrayl or more and less than 0.6Mrayl C: 0.6Mrayl or more and less than 0.7Mrayl D: 0.7Mrayl or more and less than 1Mrayl E: 1Mrayl or more

<Note to table>
"EX": Example "CEX": Comparative Example Particle size: Average primary particle size "php": 100 × Mass part of surface treatment agent / 100 parts by mass of tungsten carbide particles Comparative Example 1 is W-2 (untreated tungsten). Carbide particles) are listed in the component (C) line for comparison.
[Epoxy resin]
(A-1): Bisphenol A diglycidyl ether (“jER825” (trade name) manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 170)
(A-2): Bisphenol F diglycidyl ether ("EPICLON 830" (trade name) manufactured by DIC Corporation, epoxy equivalent 170)
(A-3): Epoxy novolak resin (manufactured by Sigma-Aldrich, product number 406775, epoxy equivalent 170)

(B-1):
Isophorone diamine (B-2):
Triethylenetetramine (B-3):
2,4,6-Tris (dimethylaminomethyl) phenol (manufactured by Nacalai Tesque, trade name "Rubeac DMP-30")
(B-4):
Polyamide amine (manufactured by DIC Corporation, trade name "laccamide EA-330")
(B-5):
Mensen Diamine (B-6):
m-phenylenediamine (B-7):
Polyetheramine T-403 (trade name, manufactured by BASF)
(B-8):
2-Ethyl-4-methylimidazole (B-9):
Hexahydrophthalic anhydride (manufactured by New Japan Chemical Corporation, trade name "Ricacid HH")

As shown in Table 2, the acoustic matching sheet of Comparative Example 1 using the untreated tungsten carbide particles had a remarkable decrease in sound velocity and a large variation in AI.
The acoustic matching sheet of Comparative Example 2 using tungsten carbide particles surface-treated with methyltrichlorosilane had poor compatibility when the particles were mixed with an epoxy resin, and the particles were unevenly dispersed due to heat generation. As a result, the sound velocity dropped significantly, and the AI variation was large.
An acoustic matching sheet of Comparative Example 3 using tungsten carbide particles surface-treated with vinyltrichlorosilane, and an acoustic matching sheet of Comparative Example 4 using tungsten carbide particles surface-treated with 3-methacryloxypropyltrimethoxysilane. For the same reason as in Comparative Example 2, the sound velocity was significantly reduced, and the AI variation was large.
On the other hand, all of the acoustic matching sheets of Examples 1 to 60 using the surface-treated tungsten carbide particles specified in the present invention can effectively suppress the decrease in sound velocity and can also suppress the variation in acoustic characteristics. I know I can do it.
All of the acoustic matching sheets of Examples 1 to 60 had sufficient AI to be used as the acoustic matching layer on the piezoelectric element side.

1 Acoustic lens 2 Acoustic matching layer 3 Piezoelectric element layer 4 Backing material 7 Housing 9 Code 10 Ultrasonic probe

Claims

A material for an acoustic matching layer containing the following components (A), (B) and (C).
(A) Epoxy resin (B) Hardener (C) Surface containing at least one of aminosilane compound, mercaptosilane compound, isocyanatosilane compound, thiocyanatosilane compound, aluminum alkoxide compound, zirconium alkoxide compound and titanium alkoxide compound. Surface-treated tungsten carbide particles surface-treated with a treatment agent
The material for an acoustic matching layer according to claim 1, wherein the component (B) contains at least one of a primary amine and a secondary amine.
The material for an acoustic matching layer according to claim 1 or 2, wherein the surface treatment agent contains at least one of an aminosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.
The material for an acoustic matching layer according to any one of claims 1 to 3, wherein the surface treatment agent contains at least one of an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.
The material for an acoustic matching layer according to any one of claims 1 to 4, wherein the surface treatment agent contains at least one of a zirconium alkoxide compound and a titanium alkoxide compound.
The material for an acoustic matching layer according to any one of claims 1 to 5, wherein the aluminum alkoxide compound contains at least one of an acetonate structure and an acetylate structure.
The material for an acoustic matching layer according to any one of claims 1 to 6, wherein the aluminum alkoxide compound contains at least one compound represented by the following general formula (1).
General formula (1): R 1a m1- Al- (OR 2a ) 3-m1
R 1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R 2a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or -SO 2 R S1. RS1 represents a substituent.
m1 is an integer of 0 to 2.
The material for an acoustic matching layer according to any one of claims 1 to 7, wherein the zirconium alkoxide compound contains at least one of an acetonate structure and an acetylate structure.
The material for an acoustic matching layer according to any one of claims 1 to 8, wherein the zirconium alkoxide compound contains at least one compound represented by the following general formula (2).
General formula (2): R 1b m2- Zr- (OR 2b ) 4-m2
R 1b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R 2b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or -SO 2 R S2. RS2 indicates a substituent.
m2 is an integer from 0 to 3.
The material for an acoustic matching layer according to any one of claims 1 to 9, wherein the titanium alkoxide compound contains at least one atom of N, P and S.
The material for an acoustic matching layer according to any one of claims 1 to 10, wherein the titanium alkoxide compound contains at least one compound represented by the following general formula (3).
General formula (3): R 1c m3- Ti- (OR 2c ) 4-m3
R 1c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group, or an unsaturated aliphatic group.
R 2c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group, or -SO 2 R S3. RS3 indicates a substituent.
m3 is an integer from 0 to 3.
The acoustic matching layer according to any one of claims 1 to 11, wherein the content of the surface treatment agent in the component (C) is 1 to 50 parts by mass with respect to 100 parts by mass of the tungsten carbide particles. material.
The material for an acoustic matching layer according to any one of claims 1 to 12, wherein the tungsten carbide particles constituting the component (C) have an average primary particle size of 1 to 10 μm.
An acoustic matching sheet obtained by curing the material for the acoustic matching layer according to any one of claims 1 to 13.
An acoustic wave probe having the acoustic matching sheet according to claim 14.
An ultrasonic probe having the acoustic matching sheet according to claim 14.
An acoustic wave measuring device including the acoustic wave probe according to claim 15.
An ultrasonic diagnostic apparatus including the acoustic wave probe according to claim 15.
A method for manufacturing an acoustic wave probe, which comprises forming an acoustic matching layer using the material for an acoustic matching layer according to any one of claims 1 to 13.